SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e41e39f5c32dc68c7919a1f250b1baf441fafa75c807ffacd3688a6967f6f5f' 
  AND token = 'Km7+P0lgnMxGFxkLu+Wjp/FnD5AbP83wFYK5pjNM8CI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}